Cigarette filter

ABSTRACT

A cigarette filter for removing nicotine and tar from cigarette smoke is composed a filtering core ( 20 ) enclosed between the tube ( 10 ) and a mouth piece ( 30 ). Multiple gaps and passages and a residue chamber ( 15 ) are individually formed between the filtering core ( 20 ) and the tube ( 10 ). Multiple inlets ( 24 ) are defined in the filtering core ( 20 ) to communicate with the tube ( 10 ), and multiple outlets ( 26 ) are defined in the filtering core ( 20 ) to communicate between the inlets ( 24 ) and the residue chamber ( 15 ). When cigarette smoke passes through the filter core ( 20 ), nicotine and tar are deposited inside the inlets ( 24 ), outlets ( 26 ) and the residue chamber ( 15 ) because they have a larger specific gravity than the other gas in the cigarette smoke.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a cigarette filter, and more particularly to a cigarette filter used to efficiently remove nicotine and tar from tobacco smoke.

[0003] 2. Description of Related Art

[0004] According to many medical reports, tobacco produces pernicious gases such as nicotine, tar and carbon monoxide when burned. Among these pernicious gases, nicotine increases the heart rate of a smoker and induces vascular problems after smoking for a long term. Tar induces chronic oppilate lung diseases such as chronic bronchitis and pulmonary emphysema. Additionally, both nicotine and tar also induce carcinogenic substances to cause great damage to a smoker's health.

[0005] Therefore, the present invention has arisen to mitigate and/or obviate the problems caused from smoking.

SUMMARY OF THE INVENTION

[0006] The main objective of the invention is to provide a cigarette filter that efficiently removes nicotine and tar from cigarette smoke.

[0007] Other advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a perspective view of a cigarette filter in accordance with the present invention;

[0009]FIG. 2 is an exploded perspective view of the cigarette filter in FIG. 1;

[0010]FIG. 3 is a cross-sectional side plan view of the cigarette filter along line 3-3 in FIG. 1; and

[0011]FIG. 4 is an operational cross-sectional side plan view of the cigarette filter in FIG. 1 showing the path of cigarette smoke.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] With reference to FIGS. 1 to 3, a cigarette filter is adapted to receive a cigarette and is substantially composed of a tube (10), a filtering core (20) and a mouth piece (30).

[0013] The tube (10) is hollow, is made of cellulose acetate and has an inner through hole with an inner surface and an inside diameter. An annular lip (11) is formed radially inward on the inner surface of the tube (10) to divide the inner through hole into a cigarette recess (13) and a core recess (14). The annular lip (11) forms a hole (12) through which the cigarette recess (13) communicates with the core recess (14).

[0014] The filtering core (20) is mounted inside the core recess (14) in the tube (10) and is also made of cellulose acetate. The filtering core (20) is a cylinder with an outside diameter slightly smaller than the inside diameter of the core recess (14) so that a narrow gap is formed between the inside surface of the tube (10) and the filtering core (20) in the core recess (14). The filtering core (20) has an inlet end and an outlet end. A first annular seat (21) is defined near the inlet end of the filtering core (20) and a second annular seat (22) is defied near the outlet end to divide the narrow gap into a middle section (B) and two end sections (A, C). An O-ring (210, 220) is mounted in each annular seat (21, 22) to seal the middle section (B) from the two end sections (A, C). A neck (23) is defined in the filtering core (20) between the first and second annular seats (21, 22) to form a residue chamber (15) to collect nicotine and tar from cigarette smoke. Multiple inlets (24) are radially defined near the inlet end of the filtering core (20) in front of the first annular seat (21). This embodiment of the cigarette filter has six inlets (24). Multiple outlets (26) are radially defined in the filtering core (20) between the first and second annular seats (21, 22). This embodiment of the cigarette filter has eighteen outlets (26). A threaded nipple (27) is axially formed on the outlet end of the filtering core (20) and extends toward and attaches to the mouth piece (30). A channel (25) is axially defined in the filtering core (20) from the inlets (24) to the outlets (26) and through the threaded nipple (27) but does not communicate with the hole (12) in the tube (10).

[0015] The mouth piece (30) has two ends, a cylindrical protrusion (33) extending from one end and a hollow bite (34) formed on the other end. The cylindrical protrusion (33) has an outer diameter the same as the inner diameter of the core recess (14) so the cylindrical protrusion (33) will tightly engage the tube (10) inside the core recess (14). A threaded hole (31) with two ends is defined in the cylindrical protrusion (33) to communicate with the channel (25) at one end and the hollow bite (34) at the other end. The threaded nipple (27) of the filtering core (20) is screwed into the threaded hole (31) in the mouth piece (30). The filtering core (20) attached to the mouth piece (30) is pressed onto the core recess (14) in the tube (10). The hollow bite (34) is adapted for a smoker to hold in the mouth.

[0016] With reference to FIGS. 3 and 4, when the smoker smokes a cigarette, cigarette smoke flows into the end section (A) of the narrow gap via the hole (12) in the tube (10) from the cigarette recess (13) and then into the channel (25) via the inlets (24) near the inlet end. When the cigarette smoke flows through the channel (25), nicotine and tar are deposited inside the channel (25) and especially inside the residue chamber (15) via the outlets (26). Because the nicotine and tar have a larger specific gravity than air (specific gravity of nicotine ortar=0.8; specific gravity of air=0.0012) and the residue chamber (15) is at a lower atmosphere then the channel (25), the residue chamber (15) efficiently attracts the deposited nicotine and tar. Therefore, about 15% of the nicotine and 85% of the tar are removed from the cigarette smoke when the smoke passing through the filtering core (20), thereby reducing the pernicious gases for the smoker.

[0017] It should be clear to those skilled in the art that further embodiments can be made without departing from the scope and spirit of the present invention. Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes can be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A cigarette filter adapted to hold a cigarette comprising: a tube (10) with two ends having an inner through hole and adapted to receive a cigarette inside the inner through hole at one end; a filtering core (20) received inside the inner through hole at the other end of the tube (10) and having an outer diameter smaller than an inner diameter of the inner through hole so that a narrow gap is formed between the tube (10) and the filtering core (20), the filtering core (20) having an inlet end, an outlet end, multiple inlets (24) defined in the inlet end, multiple outlets (26) defined near the outlet end and a channel (25) axially defined in the filtering core (20) from the inlets (24) through the outlets (26) to the outlet end; and a mouth piece (30) attached to the tube (10) to enclose the filtering core (20) inside the inner through hole; whereby when cigarette smoke flows through the tube (10) and into the filtering core (20), nicotine and tar are deposited inside the inlets (24), the channel (25) and the outlets (26) because the specific gravity of the nicotine and tar is larger than that of the other gases in the smoke.
 2. The cigarette filter as claimed in claim 1, wherein the tube (10) has an inner surface, and an annular lip (11) is formed on the inner surface to divide the inner through hole of the tube (10) into a cigarette recess (13) and a core recess (14); a hole (12) defined by the annular lip (11) so that the cigarette recess (13) communicates with the core recess (14); the filtering core (20) further has a first annular seat (21) defined near the inlet end close to the annular lip (11) and a second annular seat (22) defined near the outlet end to divide the narrow gap into a middle segment (B) and two end sections (A, C); an O-ring (210, 220) is mounted in each annular seat (21, 22) to seal the middle segment (B) from the two end sections (A, C); and a neck (23) is defined between the first and second annular seats (21, 22) to form a residue chamber (15) to collect nicotine and tar.
 3. The cigarette filter as claimed in claim 1, wherein the filtering core (20) further has a threaded nipple (27) formed on the outlet end and extending toward the mouth piece (30); and the mouth piece (30) has a cylindrical protrusion (33) and a hollow bite (34), wherein the cylindrical protrusion (33) is tightly engaged inside the tube (10); and a threaded hole (31) is defined in the cylindrical protrusion (33) to communicate with the channel (25) to engage with the threaded nipple (27) of the filtering core (20).
 4. The cigarette filter as claimed in claim 2, wherein the filtering core (20) further has a threaded nipple (27) formed on the outlet end and extending toward the mouth piece (30); and the mouth piece (30) has a cylindrical protrusion (33) and a hollow bite (34), wherein the cylindrical protrusion (33) is tightly engaged inside the tube (10) inside the core recess (14); and a threaded hole (31) is defined in the cylindrical protrusion (33) to communicate with the channel (25) to engage with the threaded nipple (27) of the filtering core (20).
 5. The cigarette filter as claimed in claim 1, wherein the filtering core (20) has six inlets (24) radially defined in the inlet end of the filtering core (20).
 6. The cigarette filter as claimed in claim 4, wherein the filtering core (20) has six inlets (24) radially defined in the inlet end of the filtering core (20).
 7. The cigarette filter as claimed in claim 1, wherein the filtering core (20) has eighteen outlets (26) radially defined near the outlet end of the filtering core (20) to communicate with the residue chamber (15).
 8. The cigarette filter as claimed in claim 4, wherein the filtering core (20) has eighteen outlets (26) radially defined near the outlet end of the filtering core (20) to communicate with the residue chamber (15). 